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2.2.12 Variance and standard deviation

2.2.12 Variance and standard deviation

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Question 2

Two samples each contain five observations. Sample A has mean 10 and Sxx=20S_{xx}=20Sxx​=20; sample B has mean 14 and Sxx=30S_{xx}=30Sxx​=30.

a.

Find the mean of the combined sample.

[1]
b.

Find SxxS_{xx}Sxx​ and the sample standard deviation for the combined sample.

[3]
Markscheme

2.2.12 Variance and standard deviation Questions

  1. A Level
  2. /Maths
  3. /2.2.12 Variance and standard deviation

8 exam-style questions on OCR (MEI) A Level Maths 2.2.12 Variance and standard deviation. Each one has a worked solution and a mark scheme showing where the marks go.

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